Method and apparatus for installing a refractory material to a surface

CROSS-REFERENCE TO RELATED APPLICATIONS

0001This application claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 12/196,756, filed Aug. 22, 2008, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

00021. Field of the Invention

0003This invention relates generally to a method and apparatus for installing a refractory material to a surface, and more particularly to a method and apparatus for installing a refractory material, which has an embedded anchor accessible via a channel, to a surface of a boiler, an industrial furnace, a heat exchanger or other vessel requiring a heat-resistant or abrasion lining.

00042. Description of the Related Art

0005To attach refractory materials to a surface of vessels, such as furnaces, boilers, heat exchangers or other vessels requiring refractory materials, the gas metal arc welding (GMAW) process may be utilized. In North America, the GMAW process is commonly referred to as MIG (metal inert gas) welding; in Europe, the process is termed MAG (metal active gas) welding. “MIG” as used hereafter refers to both the MIG and the MAG GMAW processes. To produce these welds, either MIG spot or MIG spot plug welding techniques may be used.

0006A “MIG spot weld” is a timed MIG weld in which two metal components in contact are welded together. The MIG spot weld penetrates a top metal component (e.g., an anchor for a refractory material), and in doing so welds the top metal component to a bottom metal component (e.g., a surface, such as an interior surface, or a wall of a vessel).

0007A “MIG spot plug weld” is a timed spot weld made on a top metal component that has a bore. The top metal component is welded to a bottom component using a MIG spot plug weld. The MIG spot plug weld utilizes an electrode to provide a resulting weld that sufficiently covers the bore in the top metal component and provides sufficient weld penetration to join the top metal component to the bottom metal component. A MIG spot plug weld generally requires less energy than a spot weld because it is not necessary to penetrate two steel components. Furthermore, MIG spot plug welding generally provides welds that are stronger and more consistent than MIG spot welds.

0008The weld may be made using GMAW spray transfer, GMAW globular transfer or GMAW pulsed transfer. When a spray transfer mode is utilized, a 2-, 3- or 4-component shielding gas mixture is typically used, along with sufficient current and voltage to produce a stream of weld metal or a stream of weld droplets that cascade across an open arc from the electrode to the weld site. When weld droplets are evident, the droplets will be smaller than the diameter of the electrode utilized.

0009In globular transfer mode, an open arc process is used with a reactive gas, such as Ar or CO₂. Globular transfer mode utilizes less current and voltage than in spray transfer mode. The weld droplets generated are typically larger than the electrode diameter, and the globular weld droplet transfer is irregular.

0010In pulsed transfer mode, the pulse controls the droplet frequency across an electronically modified open arc. A peak weld current and background current are applied. This process enables an open arc mode of weld transfer of minuscule weld drops. This process can further provide controlled open arc weld transfer at considerably less current than with spray transfer mode.

0011To attach the refractory material to the surface of the vessel, the most common method used by installers is to stud weld or fillet weld threaded studs on the surface of the vessel and attach carbon steel or stainless steel anchors to the studs. The refractory material is attached to the anchors and the anchors are screwed on to the studs. More specifically, the common method used by installers is to stud weld or fillet weld threaded studs on the vessel by placing a metal stud having a machined protrusion tip in the stud gun. The stud is pressed against the surface of the vessel, and when the tip of the stud is in firm contact with the vessel, the stud gun trigger is pulled and a timed current is applied through the small protrusion tip at the end of the stud. The stud weld current melts the protrusion at the end of the stud tip and a high energy arc is generated between the stud and the grounded vessel. As the stud protrusion is melted, with the force applied to the stud gun, the stud is pushed tight against a ceramic shield located at the end of the stud. The ceramic shield assists in maintaining the necessary weld arc gap and also protecting the stud weld from the atmosphere. The timed weld arc melts the tip of the stud and with the manual force applied the stud is welded to the metal surface.

0012It is therefore desirable to provide a method and apparatus for installing a refractory material to a surface that provides a simplified and streamlined approach for anchoring refractory materials without the inclusion of a stud.

0013It is further desirable to provide a method and apparatus for installing a refractory material to a surface that provides savings in materials and labor.

0014It is yet further desirable to provide a method and apparatus for installing an installation material to a surface that enhances reliability and is useful in a variety of industrial applications.

0015It is still further desirable to provide a method and apparatus for installing a refractory material to a surface that utilizes a portable welding device capable of controlled, timed activity and creating a stronger and more consistent joint between an embedded anchor of the refractory material and the surface.

0016It is yet further desirable to provide a method and apparatus for installing a refractory material to a surface that is practiced without the use of threaded studs, nuts or torque tubes, thereby reducing material costs and eliminating potential failure points.

0017It is yet further desirable to provide a method and apparatus for installing a refractory material to a surface that utilizes a welding gun having a straight or linear neck that enables a one-handed installation of the refractory material to the internal surface of the vessel.

SUMMARY OF THE INVENTION

0018In general, the invention relates to a method for installing a refractory material to a surface having the steps of inserting a nozzle and a neck of a welding gun through a channel in a refractory material; positioning the refractory material on a surface using the welding gun; firmly pushing the welding gun into the channel of the refractory material until the nozzle of the welding gun, an anchor embedded in the refractory material and the surface are in contact; welding the anchor of the refractory material to the surface with the welding gun; and removing the nozzle and the neck of the welding gun from the channel in the refractory material.

0019The method for installing the refractory material may also include confirming continuity of contact between the anchor of the refractory material and the surface. Confirming continuity of contact may be accomplished by a continuity sensor having an indicator mounted on the welding gun, such as a visual indicator, an audible indicator or combination thereof.

0020The method for installing the refractory material may further include performing a test on the step of welding the anchor using a special testing tool by inserting the special testing tool in a closed position into the channel of the refractory material; contacting a working end of the special testing tool to the anchor embedded in the refractory material; rotating an elongate handle of the special testing tool to cause the special testing tool to move from the closed position to an open position; engaging the working end of special testing tool with the anchor; applying a sufficient amount of torque to the handle of the special testing tool to test the integrity of the step of welding the anchor; rotating the handle to cause the special testing tool to move from the open position to the closed position; and removing the special testing tool from the channel in the refractory material. The test may be performed at an interval selected of after every weld, after a fixed number of welds, after a fixed period of time or at random.

0021The refractory material may be a castable monolithic, abrasion-resistant or heat-resistant lining or a precast refractory shape having the anchor embedded therein. The refractory material has a hot face positioned away from the surface and a cold face positioned against the surface. The anchor includes a rear face exposed on an exterior of the cold face of the refractory material. The anchor may include a plurality of substantially parallel, elongate protrusions protruding from a central portion of a front face of the anchor, or a protruding boss having an axial bore. The central portion of the anchor may include the bore being sized up to approximately 0.75 inch, and the anchor may have a thickness between 9 gauge and 24 gauge.

0022The welding gun of the method for installing insulation material may be a portable metal inert gas welding gun wherein the neck of the welding gun is substantially straight or linear. The neck and the nozzle of the welding gun may have a combined length greater than a thickness of the refractory material, while the neck and the nozzle of the welding gun have a diameter sufficiently large to frictionally engage the channel in the refractory material. The nozzle of the welding gun may be constructed of brass or copper, include two or more V-shaped cut-outs and be insulated.

0023The method of installing the refractory material may utilize a metal inert gas spot weld or a metal inert gas spot plug weld. In addition, the method of installing the refractory material may utilize a weld transfer mode of gas metal arc welding spray transfer, gas metal arc welding globular transfer or gas metal arc welding pulsed transfer.

0024The welding of the anchor to the surface may include providing a current and a voltage from a power source to the welding gun using a power cable, opening and closing the power source via a variable timer control configured to provide spot weld arc time between approximately 0.25 seconds and approximately 4.0 seconds; feeding an electrode from a wire feed unit to the welding gun, and supplying a flow of a shielding gas from a source of shielding gas to the welding gun via a gas hose.

0025The power source may provide the current between approximately 100 amps and approximately 450 amps and may provide the voltage between approximately 20 volts and approximately 33 volts. The electrode can be carbon steel, stainless steel, austenitic nickel-based superalloy or flux-core welding wire, with a diameter between approximately 0.035 inches and approximately 0.0625 inches. The wire feed unit may be a portable, variable speed wire feed unit having a wire feed rate between approximately 200 inches per minute and approximately 1000 inches per minute and also having a variable burnback control that may be set between approximately 0.5 inch and approximately 1.57 inches. Also, the shielding gas may include one or more gases selected from the group consisting of carbon dioxide, argon, oxygen or helium, and the flow of the shielding gas may be between approximately 10 cubic feet per hour and approximately 90 cubic feet per hour.

0026The method of installing the refractory material may also include removing a cardboard tube from the channel in the refractory material and manipulating the refractory material to fill in the channel in the refractory material. Furthermore, the method for installing the refractory material may be performed using one-hand of an installer.

BRIEF DESCRIPTION OF THE DRAWINGS

0027<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view of an example of a welding gun in accordance with an illustrative embodiment of the method and apparatus for installing a refractory material to a surface disclosed herein;

0028<figref idref="DRAWINGS">FIG. 2</figref> is a cutaway view of the nozzle of the welding gun shown in <figref idref="DRAWINGS">FIG. 1</figref> in accordance with an illustrative embodiment of method and apparatus for installing a refractory material to a surface as shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0029<figref idref="DRAWINGS">FIG. 3</figref> is a partial cutaway view of an example of a welding gun having a continuity sensor in accordance with an illustrative embodiment of the method and apparatus for installing a refractory material to a surface disclosed herein;

0030<figref idref="DRAWINGS">FIG. 4</figref> is a perspective view of an example of a welding assembly in accordance with an illustrative embodiment of the method and apparatus for installing a refractory material to a surface disclosed herein;

0031<figref idref="DRAWINGS">FIG. 5</figref> is a cutaway view of an example of a ceramic fiber module in accordance with an illustrative embodiment of the method and apparatus for installing a refractory material to a surface disclosed herein;

0032<figref idref="DRAWINGS">FIGS. 6</figref><i>a</i>, <b>6</b><i>b </i>and <b>6</b><i>c </i>are sequential illustrations showing an example of an installer installing a refractory material in accordance with an illustrative embodiment of the method and apparatus for installing a refractory material to a surface disclosed herein;

0033<figref idref="DRAWINGS">FIGS. 7</figref><i>a </i>and <b>7</b><i>b </i>are sequential illustrations showing an example of a compression and quarter-turn installation of a refractory material in accordance with an illustrative embodiment of the method and apparatus for installing a refractory material to a surface disclosed herein;

0034<figref idref="DRAWINGS">FIGS. 8</figref><i>a</i>, <b>8</b><i>b </i>and <b>8</b><i>c </i>are sequential illustrations showing an example of the removal of the cardboard tube from, and the effects of ruffling the surface of, a refractory material in accordance with an illustrative embodiment of the method and apparatus for installing a refractory material to a surface disclosed herein;

0035<figref idref="DRAWINGS">FIG. 9</figref> is a perspective view of an example of a special testing tool in a closed position in accordance with an illustrative embodiment of the special tool for testing the integrity of a weld between an anchored insulation material and a surface disclosed herein;

0036<figref idref="DRAWINGS">FIG. 10</figref> is a perspective view of an example of the special testing tool shown in <figref idref="DRAWINGS">FIG. 9</figref> in an open position in accordance with an illustrative embodiment of the special tool for testing the integrity of a weld between an anchored insulation material and a surface disclosed herein;

0037<figref idref="DRAWINGS">FIGS. 11</figref><i>a</i>, <b>11</b><i>b </i>and <b>11</b><i>c </i>are sequential illustrations showing an example of testing the integrity of a weld using a special testing tool in accordance with an illustrative embodiment of the method for testing the integrity of a weld between an anchored insulation material and a surface disclosed herein;

0038<figref idref="DRAWINGS">FIG. 12</figref> is a perspective view of an example of an embedded anchor in accordance with an illustrative embodiment of the method and apparatus for installing a refractory material to a surface disclosed herein;

0039<figref idref="DRAWINGS">FIG. 13</figref> is a cross-sectional view along line <b>13</b>-<b>13</b> of the anchor shown in <figref idref="DRAWINGS">FIG. 12</figref>;

0040<figref idref="DRAWINGS">FIG. 14</figref> is a partial cutaway view of an example of a welding gun engaging an embedded anchor in accordance with an illustrative embodiment of the method and apparatus for installing a refractory material to a surface disclosed herein;

0041<figref idref="DRAWINGS">FIG. 15</figref> is an exploded view of area <b>15</b> of the anchor and the welding gun as shown in <figref idref="DRAWINGS">FIG. 14</figref>; and

0042<figref idref="DRAWINGS">FIG. 16</figref> is a cutaway view of another example of a ceramic fiber module in accordance with an illustrative embodiment of the method and apparatus for installing a refractory material to a surface disclosed herein.

0043Other advantages and features will be apparent from the following description, and from the claims.

DETAILED DESCRIPTION OF THE INVENTION

0044The apparatuses and methods discussed herein are merely illustrative of specific manners in which to make and use this invention and are not to be interpreted as limiting in scope.

0045While the apparatuses and methods have been described with a certain degree of particularity, it is to be noted that many modifications may be made in the details of the construction and the arrangement of the apparatuses and components without departing from the scope of this disclosure. It is understood that the apparatuses and methods are not limited to the embodiments set forth herein for purposes of exemplification.

0046The description of the invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as “front,” “rear,” “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly” etc.) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the apparatuses be constructed or the method to be operated in a particular orientation.

0047The invention relates to a method and apparatus for installing a refractory material <b>30</b> to a surface <b>32</b>, such as an inner surface of a boiler, a furnace, a heat exchanger, or other vessel required to be lined with a material having a high melting point. The refractory material <b>30</b> may be any refractory material generally used in furnaces and processing equipment, such as castable monolithic, abrasion resistant or ceramic fiber module linings. The refractory material <b>30</b> may be an insulation lining constructed of a light, medium or high density refractory material, or may be an abrasion lining. In addition, the refractory material <b>30</b> can include precast refractory shapes. The refractory material <b>30</b> includes an embedded anchor <b>34</b>, which is accessible via a channel <b>44</b> in the refractory material <b>30</b>. Depending upon the particular type of refractory material <b>30</b> being installed, the anchor <b>34</b> can be constructed from suitable gage carbon steel or stainless steel.

0048The refractory material <b>30</b> has a hot face <b>60</b>, which will typically face the interior of the vessel, and a cold face <b>62</b>, which attaches to the surface <b>32</b>. The refractory material <b>30</b> includes the channel <b>44</b> running from the hot face <b>60</b> to the cold face <b>62</b>, and the channel <b>44</b> can include a cylindrical cardboard tube <b>64</b> removably seated therein. The channel <b>44</b> of the refractory material <b>30</b> enables the refractory material <b>30</b> to be picked up by the welding gun <b>10</b> and enables an installer <b>46</b> to access the anchor <b>34</b> so that the anchor <b>34</b> and the refractory material <b>30</b> may be joined to the surface <b>32</b> using one hand.

0049A rear face <b>68</b> of the anchor <b>34</b> is exposed on an exterior of the cold face <b>62</b> of the refractory material <b>30</b>, such that it makes direct contact with the surface <b>32</b>. As shown in <figref idref="DRAWINGS">FIG. 5</figref>, a front face <b>70</b> of a central portion <b>72</b> of the anchor <b>34</b> includes a plurality of elongate protrusions <b>74</b>. Each of the elongate protrusions <b>74</b> is substantially parallel and protrudes from the anchor <b>34</b> towards the hot face <b>60</b> of the refractory material <b>30</b> along the channel <b>44</b>. As shown in <figref idref="DRAWINGS">FIG. 16</figref>, the front face <b>70</b> of the central portion <b>72</b> of the anchor includes a protruding boss <b>94</b> with a bore <b>96</b>. A person having ordinary skill in the art will appreciate that there are a number of variations in the design of the embedded anchor <b>34</b> and how support is provided within the refractory material <b>30</b>.

0050Referring now to the figures of the drawings, wherein like numerals of reference designate like elements throughout the several views, and initially to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, a welding gun <b>10</b>, which can be a standard MIG welding gun, a manual MIG welding gun or a MIG welding gun capable of variable speed, motorized drive rolls (i.e., a “push pull gun”), exerts a pulling force on an electrode <b>28</b> at the same time the electrode <b>28</b> is pushed from a wire feed unit <b>54</b>. The welding gun <b>10</b> includes a handle <b>12</b>, a neck <b>14</b>, a control switch or trigger <b>16</b>, a nozzle <b>18</b>, a power cable <b>20</b> and a gas hose <b>22</b>. A gas nozzle <b>24</b> and a contact tip <b>26</b> are located within the nozzle <b>18</b> of the welding gun <b>10</b>. The nozzle <b>18</b> is affixed at a terminal end of the neck <b>14</b> of the welding gun <b>10</b>, opposite the handle <b>12</b>.

0051Unlike current straight-necked MIG welding guns, the neck <b>14</b> of the welding gun <b>10</b> is straight or linear and has a sufficient length to pass through the refractory material <b>30</b> to be installed. In addition, the diameter of the neck <b>14</b> of welding gun <b>10</b> should be sufficiently large to frictionally engage the refractory material <b>30</b> for hoisting and positioning during installation. There may be approximately 0.5 inch clearance between the handle <b>12</b> of the welding gun <b>10</b> and insulation material <b>30</b>.

0052Thus, the welding gun <b>10</b> serves at least two distinct functions, apart from the welding function. The welding gun <b>10</b> having a straight or linear neck <b>14</b> holds and supports the refractory material <b>30</b> during the installation and joining of an anchor <b>34</b> of the refractory material <b>30</b> to the surface <b>32</b>. Further, the straight or linear neck <b>14</b> of the welding gun <b>10</b> having a sufficient diameter to frictionally engage the refractory material <b>30</b> enables a one handed installation of the refractory material <b>30</b> to the surface <b>32</b>.

0053The nozzle <b>18</b> of the welding gun <b>10</b> may be insulated in order to isolate the energized contact tip <b>26</b> from the nozzle <b>18</b>. The nozzle <b>18</b> of the welding gun <b>10</b> may also include two or more V-shaped cut-outs at a terminal end. The cut-outs enable a shielding gas <b>56</b> to escape from the nozzle <b>18</b> of the welding gun <b>10</b> when the weld is made and while the nozzle <b>18</b> of the welding gun <b>10</b> is in contact with the surface <b>32</b>. The nozzle <b>18</b> of the welding gun <b>10</b> may be constructed of brass or copper.

0054The welding gun <b>10</b> may be equipped with a continuity sensor <b>36</b> as shown in <figref idref="DRAWINGS">FIG. 3</figref>. Since consistent and high quality MIG spot welds and MIG spot plug welds require solid contact between the anchor <b>34</b> and the surface <b>32</b> (i.e., vessel or other surface to be insulated), the continuity sensor <b>36</b> ensures proper contact between the anchor <b>34</b> and the surface <b>32</b>. The continuity sensor <b>36</b> may utilize low-voltage to detect when the anchor <b>34</b> and the surface <b>32</b> are in direct contact. The continuity sensor <b>36</b> may be integrated into the welding gun <b>10</b>. The continuity sensor <b>36</b> may include a separate power source <b>38</b>, such as a 9-volt battery. The continuity sensor <b>36</b> may be electrically connected to the nozzle <b>18</b> of the welding gun <b>10</b> using an electrical wire <b>40</b>.

0055During operation, the nozzle <b>18</b> and the neck <b>14</b> of the welding gun <b>10</b> are inserted into the channel <b>44</b> in the refractory material <b>30</b> until making contact with the anchor <b>34</b> embedded within the refractory material <b>30</b>. The installer <b>46</b> pushes the welding gun <b>10</b> forward until the nozzle <b>18</b> of the welding gun <b>10</b>, the anchor <b>34</b> and the grounded surface <b>32</b> to be insulated are in contact. When the nozzle <b>18</b> of the welding gun <b>10</b>, the anchor <b>34</b>, and the grounded surface <b>32</b> are in metal-to-metal contact, a circuit is completed and a continuity of low voltage is sensed resulting in an indicator <b>42</b> (e.g., a visual indicator, such as an LED, or an audible indicator, such as a tone or a beep emitted from a speaker) to be activated. The indicator <b>42</b> may be mounted on or integrated into the welding gun <b>10</b> to alert the installer <b>46</b> of continuity, such as on the handle <b>12</b> of the welding gun <b>10</b>.

0056Referring now to <figref idref="DRAWINGS">FIG. 4</figref>, connected to the welding gun <b>10</b> is a suitable GMAW power source <b>48</b>. The power source <b>48</b> may be a constant voltage power source, for example a portable constant voltage unit, such as the Miller® XMT™ 350 CC/CV Auto-Line™ (MILLER ELECTRIC MFG. CO., Appleton, Wis.), a generator, an inverter or a pulsed MIG power source. A variable timer control <b>50</b> is configured to open and close the power source <b>48</b>. The timer control <b>50</b> specifies the spot weld arc time, which may be set between approximately 0.25 seconds and approximately 4.0 seconds. The timer control <b>50</b> aids in quality control by providing a weld time that is both accurate and consistent. To ensure a correct time, a calibrated digital time readout <b>52</b> may be provided with the power source <b>48</b> and the timer control <b>50</b>. The readout <b>52</b> may be located at a wire feed unit <b>54</b> or may also be located in proximity to the installer <b>46</b> to permit convenient viewing. The power source <b>48</b> provides a weld current between approximately 100 amps and approximately 450 amps and provides a voltage between approximately 20 volts and approximately 33 volts.

0057The electrode <b>28</b> may be supplied by way of the wire feed unit <b>54</b>, such as a portable, variable speed MIG wire feed unit, for example the Miller® SuitCase 12RC (MILLER ELECTRIC MFG. CO., Appleton, Wis.). The electrode <b>28</b> feed rate may range from approximately 200 inches per minute to approximately 1000 inches per minute. Supplied to the wire feed unit <b>54</b> on a reel or spool, the electrode <b>28</b> may be any suitable material, including but not limited to carbon steel, such as 70S-3 or 70S-6 carbon steel, stainless steel, such as 304, 308, 309 or 310 stainless steel, or austenitic nickel-based superalloys, such as Inconel® alloy 601 (SPECIAL METALS CORP., Huntington, W. Va.). Electrode <b>28</b> diameters of approximately 0.035 inch (approximately 0.9 mm) to approximately 0.0625 inch (approximately 1.6 mm) may be utilized.

0058The wire feed unit <b>54</b> may include a variable burnback control. The burnback setting may be between approximately 0.5 inch (15 mm) and approximately 1.57 inches (40 mm). An electrode extension may also be utilized to minimize electrode <b>28</b> burnback to the contact tip <b>26</b> of the welding gun <b>10</b> as each timed weld is made. A short contact tip <b>26</b> and a long nozzle <b>18</b> for the welding gun <b>10</b> assist in providing the correct electrode extension from the contact tip <b>26</b> of the welding gun <b>10</b> to the work surface <b>32</b>.

0059The gas nozzle <b>24</b> of the welding gun <b>10</b> is in fluid communication with a source of shielding gas <b>56</b>. The shielding gas <b>56</b> is passed through the gas hose <b>22</b> to the gas nozzle <b>24</b> of the welding gun <b>10</b>. The shielding gas <b>56</b> may be selected from the following gases: a single reactive shielding gas, such as Ar or CO₂; a two-component shielding gas mixture, such as Ar/CO₂, Ar/O₂or Ar/He; a three-component shielding gas mixture, such as Ar/CO₂/O₂, Ar/CO₂/He, or Ar/O₂/He; or a four-component shielding gas mixture, such as Ar/CO₂/O₂/He. For example, 90% He, 25% CO₂, 98% Ar and 2% O₂, 85% Ar and 15% CO₂, 80% Ar and 20% CO₂, or 75% Ar and 25% CO₂shielding gas mixtures may be utilized; however, the selection of a specific shielding gas mixture is dependent upon the particular welding application. The shielding gas <b>56</b> may be delivered at a flow rate of between approximately 10 cubic feet per hour to approximately 90 cubic feet per hour, for example, between approximately 34 cubic feet per hour and approximately 45 cubic feet per hour. The shielding gas <b>56</b> may be eliminated with the use of flux-core welding wire as the electrode <b>28</b>.

0060In general during operation, the nozzle <b>18</b> of the welding gun <b>10</b> is pressed to the anchor <b>34</b> and the trigger <b>16</b> of the welding gun <b>10</b> is pressed by the installer <b>46</b> initiating the wire feed unit <b>54</b>, a timed current and voltage to be supplied from the power source <b>38</b> and a flow of shielding gas <b>56</b>, resulting in an electric arc to be struck. The wire feed unit <b>54</b> supplies the electrode <b>28</b> to the welding gun <b>10</b> by driving it through an electrode conduit, which guides and protects the electrode <b>28</b>, and onto the contact tip <b>26</b>. The contact tip <b>26</b> of the welding gun <b>20</b> is connected to the power source <b>48</b> through the power cable <b>20</b> and transmits the electrical energy to the electrode <b>28</b> while directing it to the surface <b>32</b> and the anchor <b>34</b> to be welded. The contact tip <b>26</b> allows passage of the electrode <b>28</b> therethrough while maintaining contact with the anchor <b>34</b>. There are a number of factors that affect the specific weld current and voltage utilized with the method and apparatus for installing refractory materials <b>30</b> on the surface <b>32</b>, including equipment, the composition of the material used to construct the anchor <b>34</b> of the refractory material <b>30</b>, the thickness of the anchor <b>34</b>, the size, if any, of a bore in the anchor <b>34</b>, the composition of the surface <b>32</b> onto which the anchor <b>34</b> is to be welded, the type of electrode <b>28</b>, the feed rate of the electrode <b>28</b>, the type of shielding gas <b>56</b>, the shielding gas <b>56</b> flow rate, the burnback setting and the environment, such as temperature and humidity.

0061Referring now to <figref idref="DRAWINGS">FIGS. 6 through 8</figref>, depicting an illustrative manner in which the method and apparatus for installing the refractory material <b>30</b> to the surface <b>32</b> may be practiced. An insulation installer <b>46</b> may be situated inside of a vessel having the surface <b>32</b> to be insulated and in proximity to a supply of refractory materials <b>30</b>. Also situated within the vessel is the welding gun <b>10</b>, which is connected to the wire feed unit <b>54</b> by way of the electrode <b>28</b>. The power source <b>48</b> is connected to the welding gun <b>10</b> by way of the power cable <b>20</b>. Also connected to the welding gun <b>10</b> by way of the gas hose <b>22</b> is the source of shielding gas <b>56</b>. The power source <b>38</b> does not need to be in the immediate vicinity of vessel; the only proximity limitation is the length of the power cable <b>20</b>, which may be 400 feet or more.

0062For purposes of exemplification, the refractory material <b>30</b> is illustrated as a ceramic fiber module <b>58</b>, but the method and apparatus disclosed herein should not be so limited. The method and apparatus disclosed herein may be utilized with any suitable refractory material, such as precast refractory shapes, ceramic fiber modules, abrasion linings, etc., having an embedded anchor. As shown in <figref idref="DRAWINGS">FIG. 5</figref>, the ceramic fiber module <b>58</b> is generally rectangular and includes of a plurality of tightly packed carbon fiber or ceramic sheets stacked side by side. The ceramic fiber module <b>58</b> may come in various dimensions, such as about twelve (12) inches by about twelve (12) inches, about twelve (12) inches by about six (6) inches, about twenty-four (24) inches) by about twenty-four (24) inches, etc., with a thickness ranging anywhere from about four (4) inches to about sixteen (16) inches. The ceramic fiber module <b>58</b> has a hot face <b>60</b>, which will typically face the interior of the vessel, and a cold face <b>62</b>, which attaches to the surface <b>32</b>. The ceramic fiber module <b>58</b> includes a central axial channel <b>44</b> running from the hot face <b>60</b> to the cold face <b>62</b>, and as illustrated in <figref idref="DRAWINGS">FIG. 5</figref> includes a cylindrical cardboard tube <b>64</b> removably seated therein. Once the ceramic fiber module <b>58</b> is installed on the surface <b>32</b> and the resulting installation is tested, the cardboard tube <b>64</b> may be removed and the channel <b>44</b> effectively closed by manually ruffling the ceramic fiber sheets as illustrated in <figref idref="DRAWINGS">FIG. 8</figref>. The channel <b>44</b> of the ceramic fiber module <b>58</b> enables the module <b>58</b> to be picked up by the welding gun <b>10</b> and enables the installer <b>46</b> to access the anchor <b>34</b> so that the anchor <b>34</b> and the ceramic fiber module <b>58</b> may be welded to the surface <b>32</b> using one hand.

0063Embedded within the ceramic fiber module <b>58</b> at the cold face <b>62</b> are the anchor <b>34</b> and two parallel support rods <b>66</b> interconnected with opposing ends of the anchor <b>34</b>. A rear face <b>68</b> of the anchor <b>34</b> is exposed on an exterior of the cold face <b>62</b> of the ceramic fiber module <b>58</b>, such that it may make direct contact with the surface <b>32</b>. The support rods <b>66</b> within the ceramic fiber module <b>58</b> run parallel to the cold face <b>62</b> and the surface <b>32</b> to be insulated. As shown in <figref idref="DRAWINGS">FIG. 5</figref>, a front face <b>70</b> of a central portion <b>72</b> of the anchor <b>34</b> may include a plurality of elongate protrusions <b>74</b>. Each of the elongate protrusions <b>74</b> is substantially parallel and protrudes from the anchor <b>34</b> towards the hot face <b>60</b> of the ceramic fiber module <b>58</b> along the channel <b>44</b>. It will be appreciated that there are a number of variations in anchor <b>34</b> design and how support is provided within the ceramic fiber module <b>58</b>.

0064As shown in <figref idref="DRAWINGS">FIGS. 12 and 13</figref>, the front face <b>70</b> of the anchor <b>34</b> may include the protruding boss <b>94</b> with the bore <b>96</b> within the central portion <b>72</b>. The bore <b>96</b> may be annular, ovate, rectangular, square or any other shape in cross-section. The diameter of the bore <b>96</b> depends upon the particular welding application and may range from approximately zero (0) inches (for MIG spot welds) up to approximately 0.75 inch. The anchor <b>34</b> having the bore <b>96</b> are installed using MIG spot plug welds, whereas the anchor <b>34</b> without the bore <b>96</b> are installed using MIG spot welds. The length of the bore <b>96</b> may also vary depending upon the particular welding application. As shown in <figref idref="DRAWINGS">FIG. 14</figref>, the protruding boss <b>94</b> is sized and shaped to be received within the nozzle <b>18</b> of the welding gun such that the electrode <b>28</b> passes through the bore <b>96</b> to make direct contact with the surface <b>32</b>. When properly aligned for installation of the refractory material <b>30</b> to the surface, the electrode <b>28</b>, the nozzle <b>18</b>, the boss <b>94</b> and the bore <b>96</b> are generally coaxially aligned. The bore <b>96</b> of the protruding boss <b>94</b> aids in retaining welding material for improved weld penetration during installation of the refractory material <b>30</b>.

0065The composition of material of the anchor <b>34</b> may be any suitable material, such as carbon steel or stainless steel. The anchor <b>34</b> may have a thickness from approximately 24 gauge (0.0239 inches/0.607 mm) to approximately 9 gauge (0.1495 inches/3.797 mm). The composition of material of the surface <b>32</b> to be insulated may be any suitable material, and the thickness of the surface <b>32</b> of the vessel may be any thickness, depending upon the vessel, such as a thickness from approximately 11 gauge (0.1196 inches/3.03784 mm) to approximately 0.5 inch (12.7 mm).

0066Referring now to <figref idref="DRAWINGS">FIGS. 6 through 8</figref>, the installer <b>46</b> inserts the nozzle <b>18</b> and the neck <b>14</b> of the welding gun <b>10</b> into the channel <b>44</b> of the refractory material <b>30</b> to access the embedded anchor <b>34</b> closest the hot face <b>60</b> of the refractory material <b>30</b>. The nozzle <b>18</b> of the welding gun <b>10</b> should make contact with the front face <b>70</b> of the anchor <b>34</b>. The welding gun <b>10</b> is then used to lift or hoist the refractory material <b>30</b> into a desired position on the surface <b>32</b>. Once the refractory material <b>30</b> is properly positioned on the surface <b>32</b>, the installer <b>46</b> holds the welding gun <b>10</b> substantially perpendicular to the surface <b>32</b> and firmly pushes the welding gun <b>10</b> into the refractory material <b>30</b> until the nozzle <b>18</b> of the welding gun <b>10</b>, the anchor <b>34</b> and the surface <b>32</b>, which is grounded, are in metal-to-metal contact. The contact of the nozzle <b>18</b> of the welding gun <b>10</b>, the anchor <b>34</b> and the surface <b>32</b> may be verified with the use of the continuity sensor <b>36</b> integrated into the welding gun <b>10</b>; in such case, the indicator <b>42</b> of the continuity sensor <b>36</b> will indicate to the installer <b>46</b> when contact is obtained between the nozzle <b>18</b> of the welding gun <b>10</b>, the anchor <b>34</b> and the surface <b>32</b>. Once continuity of contact has been achieved (and possibly verified using the continuity sensor <b>36</b>), the installer <b>46</b> maintains constant pressure to maintain contact and activates the welding gun <b>10</b> by way of the control switch or trigger <b>16</b>. The timer control <b>50</b> specifies the spot weld arc time, which may be set between approximately 0.25 seconds and approximately 4.0 seconds. The welding gun <b>10</b> may be removed from the channel <b>44</b> once the refractory material <b>30</b> is installed on the surface <b>32</b>.

0067Referring now to <figref idref="DRAWINGS">FIG. 7</figref>, subsequent installation of additional ceramic fiber modules <b>58</b> is typically performed in an alternating, quarter-turn fashion, such as that utilized in the installation of parquet flooring tiles. Because of the arrangement of the individual ceramic fiber sheets and the support rods <b>66</b> of the ceramic fiber module <b>58</b>, the ceramic fiber module <b>58</b> is typically compressible in a first direction, but not in a second direction. In such a case, the installer <b>46</b> uses his or her free hand to compress the ceramic fiber module <b>58</b> a single direction, depending upon the orientation of the ceramic fiber module <b>58</b>. A person having ordinary skill in the art will appreciate that when other types of refractory materials <b>30</b>, such as precast refractory shapes, the installer <b>46</b> may install the refractory material <b>30</b> in an alternative fashion depending upon the particular dimensions, shape and other configurations of the vessel, the refractory material <b>30</b> and/or the anchor <b>34</b> embedded in the refractory material <b>30</b>.

0068Once at least one of the refractory materials <b>30</b> is installed, the integrity of the installation may be tested using a special testing tool <b>76</b>. The special testing tool <b>76</b> can test the torque strength of the installation, which may then be correlated to tensile load. The torque strength of the installation is highly dependent upon the composition of the materials (i.e., the anchor and the surface) present in the installation. As an example, the torque strength of the installation may be at least approximately thirty (30) inch-pounds, which may then be correlated to tensile strength depending upon the composition of the materials involved in the installation.

0069As illustrated in <figref idref="DRAWINGS">FIGS. 9 through 11</figref>, the special testing tool <b>76</b> includes a working end <b>78</b> with an opposing elongate handle <b>80</b>. The elongate handle <b>80</b> of the special testing tool <b>76</b> should be longer than the thickness of the refractory materials <b>30</b>. The working end <b>78</b> of the special testing tool <b>76</b> includes a pair of teeth <b>82</b> capable of being moved between an open position (<figref idref="DRAWINGS">FIG. 10</figref>) and a closed position (<figref idref="DRAWINGS">FIG. 9</figref>). The working end <b>78</b> of the special testing tool <b>76</b> may include a pivot support plate <b>84</b> and a fixed support plate <b>86</b> with the pair of teeth <b>82</b> being pivotally attached therebetween using a pair of corresponding shafts <b>88</b>. The fixed support plate <b>86</b> may be attached to a terminal end of the elongate handle <b>80</b>, and the pivot support plate <b>84</b> may be linked to the fixed support plate <b>86</b> via a central bearing shaft <b>90</b>.

0070As sequentially illustrated in <figref idref="DRAWINGS">FIG. 11</figref>, to test the installation of the refractory materials <b>30</b>, if present, the cardboard tube <b>64</b> embedded in the channel <b>44</b> should be removed from the elongate protrusions <b>74</b> of the anchor <b>34</b>. In the closed position, the special testing tool <b>76</b> may then be inserted into the refractory materials <b>30</b> until the pivot support plate <b>84</b> engages the front face <b>70</b> of the anchor <b>34</b> between the elongate protrusions <b>74</b>. Upon engagement between the pivot support plate <b>84</b> and the front face <b>70</b> of the anchor <b>34</b>, the handle <b>80</b> of the special testing tool <b>76</b> may be rotated, such as in a counterclockwise motion, causing the pivot support plate <b>84</b> to rotate about the central bearing device <b>90</b>, resulting in the teeth <b>82</b> pivoting about the shafts <b>88</b> from the closed position to the open position. In the open position, the teeth <b>82</b> of the working end <b>78</b> of the special testing tool <b>76</b> engage the elongate protrusions <b>74</b> on the front face <b>70</b> of the anchor <b>34</b>. With the teeth <b>82</b> of the special testing tool <b>76</b> engaged with the elongate protrusions <b>74</b> of the anchor <b>34</b>, a torque wrench <b>92</b> may engage, or be incorporated, a portion of the handle <b>80</b> of the special testing tool <b>76</b> outside of the refractory materials <b>30</b>. The torque wrench <b>92</b> may then be rotated until the torque wrench <b>92</b> “snaps” indicating the pre-set foot-pound requirements have been met. Once the integrity of the installation has be tested, the handle of the special testing tool <b>76</b> may be rotated, such as in a clockwise motion, causing the teeth <b>82</b> to disengage the elongate protrusions <b>74</b> of the anchor <b>34</b> and move from the open position to the closed position. Once disengaged, the special testing tool <b>76</b> may be removed from the refractory materials <b>30</b>. As shown in <figref idref="DRAWINGS">FIG. 8</figref>, the cardboard tube <b>64</b>, if present, may be removed from the refractory materials <b>30</b> and the channel <b>44</b> effectively closed by manually ruffling the ceramic fiber sheets. The test may be performed after every weld, after a fixed number of welds, after a fixed period of time or at random.

0071Whereas, the apparatuses and methods have been described in relation to the drawings and claims, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention.